The present application claims priority to Swedish Patent Application No. 0102443-9 filed Jul. 9, 2001. Said application is expressly incorporated herein by reference in its entirety.
1. Technical Field
The present invention is concerned with an anti-reversing device fitted in a staple magazine with is accommodated in a stapler and which contains elongated staple blanks which are separably joined with each other along their long sides to form a continuous web. The separable joint is disposed along the midsection portions of the staple blanks. The outer sections of each staple blank are capable of limited movement relative to the outer portions of adjacent staple blanks and to their own aforementioned midsections portion in a direction which is traverse to the lengthwise direction of the web. In use, the staple blanks are advanced stepwise by a feed device along a feed channel out of a containing magazine, one at a time, via a outlet opening from the magazine. The feed channel consists of at least first and second channel guides on which the continuous web of the staple blanks advances. The first and second channel guides are positioned so that each supports a respective outer portion of the web. A third channel guide is provided that, along the center portion of the web, abuts closely thereon at an opposite to the side of the web that is supported by the first and second channel guides.
2. Background of the Invention
Staple magazines of the type described above are known. Since forces arise that act on the web in a direction that is opposed to the feed direction out of the magazine, it has been found necessary to provide the magazine with an anti-reversing device that counteracts these opposed forces. Such anti-reversing devices have been known to consist of a piece of a material exhibiting an edge which is tensioned against the web and engages in the interstices between the joined staple blanks. The drawback of these devices, however, has been that they are difficult to mount correctly, resulting in their intended functionality not being attained. Moreover, because the piece of material is most often fabricated of metal while the magazine consists primarily of plastic, it is more difficult to recycle the magazine after the staple blanks are spent. Since the piece of material would first have to be separated from the magazine before recycling can take place, a process generally considered to be difficult, result is frequently that no recycling takes place of any of the magazine.
The present invention obviates the above-mentioned drawbacks by the inclusion of a reversing device in which the first and the second channel guides exhibit, at equal distances from the outlet opening at the inside of the magazine, respective integrated stops which, as the web of staples is advanced, force the outer sections of each staple blank to bend resiliently upwards relative to a center portion thereof as the staple blank passes over the substantially parallel stops. After passing over the stops, the two outside portions regain their original configuration once the stops are passed. In this way, as a staple blank feeds past the stops, it is prevented by the stops from moving in the direction opposite to the direction of feed.
The invention is further characterized in that each stop projects above a top surface of its respective channel guide to a height equal to at least half the height of a staple blank.
Still further, each stop is of substantially triangular cross-sectional shape, when taken in an elevational view, with one side of the triangle coinciding with the top of the associated channel guide, and the side nearest to the outlet opening having a rake angle not exceeding 90 degrees relative to the side coinciding with the top of the channel guide.
The present invention is further characterized in that the rake angle may range between 70 and 110 degrees.